You must explain（）how they succeeded（）the experiment.

单项选择题We（）every day when we were children.

A.used to swim
B.used to swimming
C.use to swim
D.use to swimming

单项选择题We must make a difference between（）language and（）language.

A.spoken；written
B.speaking；written
C.speaking；writing
D.speak；write

单项选择题What a fool I have been! Why（）I think of that before?

A.don’t
B.didn’t
C.not
D.do

单项选择题---Which do you like better, real movies（）cartoons? -- I prefer cartoons （）real movies.

A.and；than
B.or；than
C.and；and
D.or；to

单项选择题--- What's happened to Tom? ---（）to hospital.

A.He’s taken
B.He’ll be taken
C.He’ll take
D.He’s been taken

单项选择题The bedroom needs（）

A.decorating
B.to decorate
C.decorate
D.decorated

单项选择题They（）the train until it disappeared in the distance

A.saw
B.watched
C.noticed
D.observed

单项选择题Time is money! We should（）our time.

A.be fit for
B.make good use of
C.play a part of
D.take the place of

单项选择题She has lived here（）three years.

A.since
B.for
C.during
D.in

单项选择题She's unlucky, and she's always suffering（） luck one after another

A.a sick
B.an ill
C.sick
D.ill